French patent No. 90 07425 filed by the common corporate assignee (published under No. 2 663 456 and corresponding to U.S. Ser. No. 692,421 now U.S. Pat. No. 5,164,559) relates to a circuit breaker with incorporated varistance, and including a device for inserting the varistance while the circuit breaker is opening. In that device, the varistor is constituted by a stack of pellets preferably made of metal oxides based on zinc oxide. The pellets form a cylindrical column coaxial with the casing of the circuit breaker. Resistive pellets may be connected in series therewith by extending the stack. They serve to limit power in the varistor components. The entire stack is housed inside a non-sealed insulating tube.
A single stack of varistor and resistor pellets occupies a considerable vertical height and requires the circuit breaker to be extended upwards.
The object of the present invention is to make the varistor and resistor device more compact by significantly reducing its height.